| dc.description.abstract | This thesis presents an autonomous landing system designed for an fixed-wing unmanned
aerial vehicle (UAV) to land in a net suspended by multirotor UAVs. Ordinary landing
of an fixed-wing UAV usually involves landing on a long runway, but by landing in a
net suspended below multirotor UAVs, operations with fixed-wing UAV can be performed
from ships or other platforms with confined space where no runway is available. The focus
in this thesis is placed on the fixed-wing UAV part of the landing, and involves design and
implementation of a guidance and control system, together with a system for coordinating
a landing path between the fixed-wing UAV and the multirotor UAVs.
The autonomous landing system uses the Pixhawk autopilot for low-level control, and a
software toolchain from Underwater Systems and Technology Laboratory (LSTS), Porto,
for high-level guidance and control, mission review and communication. The guidance
and control system developed in this thesis is implemented in the LSTS toolchain, and
consist of a decoupled lateral and longitudinal line-of-sight (LOS) guidance scheme for
pitch and roll angle commands, and a speed controller for throttle command.
The system is tested both in software-in-the-loop (SITL) simulations and flight experiments
at Agdenes airfield, where successful tests demonstrated both the feasibility and the
good performance of the system using a Skywalker X8 fixed-wing UAV. | |
